Bale stripping machines or bale openers are used to release fibers or fiber flocks from pressed fiber bales. To do so, a stripping element is moved over the fiber bales. The stripping element is mounted on a stripping arm, which is adjusted in height on the present fiber bales. The stripping arm is in turn held on a stripping tower. The stripping tower makes it possible for the stripping element to be movable over the surface of the fiber bales to be stripped. The stripping arm is arranged on a running gear or a bogie. With a running gear, which is usually guided on rails, it is possible to move along a row of bales. If the fiber bales are arranged in a circle around the stripping tower, the stripping tower is arranged on a bogie. A combination of a running gear and a bogie is used when fibers or fiber flocks are stripped from a first row of fiber bales in one direction and then from a second row of fiber bales in the opposite direction.
The bale opener stands at the beginning of process lines in preparation for a spinning mill (opening room) for processing fiber materials, for example, cotton or synthetic fibers or mixtures thereof, and has a crucial influence on the continuity of the processes inside the spinning mill preparation. In the bale opener, the fiber materials supplied in bales are released from the bales by stripping off the fiber flocks and then transferred to a pneumatic transport system. The pneumatic transport system takes the fiber flocks through pipelines to the downstream cleaning machines.
In the bale openers conventionally used today, the stripping arm is mounted in a height-adjustable mount on the stripping tower. The height adjustment usually takes place by means of chain or belt drives on which the stripping arm is raised or lowered. To determine the position of the stripping arm in relation to the surface of the fiber bales, sensors are provided on the stripping arm.
Various embodiments of lifting gear for stripping arms are known from the prior art. For example, CH 686 188 A5 discloses a stripping arm with a chain drive for the height adjustment. The stripping arm is suspended by a cable and pulleys on a counterweight, wherein the stripping arm is adjustable in height with a lifting motor by means of a chain drive.
CH 675 386 A discloses a bale opener which moves the stripping arm in a circular pattern over the fiber bales to be opened. The stripping arm is adjusted in height by means of four threaded rods arranged at the corners. The stripping arm is raised or lowered by rotating the threaded rods simultaneously. The threaded rods are connected by a gear to ensure a synchronized movement of the threaded rods.
One disadvantage of the known design according to the prior art is the complex sensor system which is necessary for detection, adjustment and the operationally required adjustment of the position of the stripping arm.